Chapter 4: Carbon and the Molecular Diversity of Life (Checked at 9:00 PM 12/11/10. Ch 4 looks fine. Ch 5 only finished through lipids)Functional Groups

Hydroxyl
Carbonyl
Carboxyl
Amino
Sulfydryl
Phosphate
Methyl
Structure
-OH
C=O
-COOH
-NH2
-SH
-OPO3
-CH3
Name of Compounds
Alcohols (usually end in –ol)
Ketones (if the carbonyl group is within a carbon skeleton)
Aldehydes (if the carbonyl groups is at the end of the carbon skeleton)
Carboxylic Acids (organic acids)
Amines
Thiols
Organic Phosphates
Methyl
Functional Properties
Polar as a result of the electronegative oxgen atom drawing electrons toward itself
Attracts water molecules,helping dissolve organic compounds such as sugars
A ketone and aldehyde may be structural isomers with different properties
Has acidic properties because it is a source of hydrogen ions
The covalent bond between oxygen and hydrogen is so polar that hydrogen ions tend to dissociate reversibly
Acts as a base; can pick up a proton from the surrounding solution.
Two sulhydryl groups can interact to help stabilize protein structure
Makes the molecule of which is is a part an anion (negatively charged ion)
Can transfer energy between organic molecules
Makes molecules nonpolar

Pictures taken from Campbell Biology Online E-Book


Important Concepts
Organic Chemistry – the study of carbon compounds
Hydrocarbons – Organic moleclues that consist of only carbon and hydrogen atoms
Tetravalence – The carbon completes its valence shell by sharing electrons with other atoms in four covalent bonds. This makes a large, complex molecule possible.
Isomers – Compounds that have the same molecular formula but different structures.Therefore, they have different chemical properties.
o Structural Isomers – Molecules that have the same molecular formula but differ inthe covalent arrnagement of atoms
o Geometric Isomers – Compounds with the same covalent partnerships that differ in the spatial arrangement of atoms around a carbon-carbon double bond.
Enantiomers – Molecules that are mirror images of each other
o Levo-Isomer: Left Handed
o Dextra-Isomer: Right Handed
Living matter consists mainly of: Carbon, Oxygen, Hydrogen, Nitrogen, Sulfur, and Phosphorus
Carbon (with its four covalent bonds) is the basiv building block in molecular architecture.


Chapter 5: The Structure and Function of Macromolecules

Overview-The Molecules of Life
- Each type of small molecule has unique properties from the arrangement of their atoms
- The four main classes of large biological molecules are: carbohydrates, lipids, proteins, and nucleic acids

5.1: Most Macromolecules are Polymers, built from Monomers
- Carbohydrates, proteins, and nucleic acids are chain like molecules called polymers
- A polymer is a long molecule with many similar or identical building blocks linked by a covalent bond.
- Smaller building blocks of a polymer is called a monomer

The Synthesis and Breakdown of Polymers
- Monomers are connected by a reaction in which two molecules are covalently bonded to each other through loss of a water molecule called condensation reaction (dehydration reaction) -- the molecule lost is water
- When a bond forms between two monomers each monomer contributes part of the water molecule that is lost--hydroxyl group (-OH) and hydrogen (-H)
- This process is repeated to form a polymer
- Cell must expend energy to have dehydration reactions and with the help of enzymes
- Polymers are broken down to monomers by hydrolysis - this process is essentially the reverse of dehydration reaction -- means to break with water
- Bonds between monomers are broken down by the addition of water molecules -- a hydrogen from the water attaching to one monomer and a hydroxyl group attaching to the adjacent monomer (Ex. digestion in our bodies)

The Diversity of Polymers
- Each cell has thousands of kinds of macromolecules -- varies between types of cells
- Difference between human siblings is in the variation in polymers -- DNA and proteins
- Monomers are constructed from 40-50 common monomers (Ex. proteins are made up of 20 different amino acids in a chain)
- Small molecules common to all organisms are ordered into unique macromolecules

5.2: Carbohydrates Serve as Fuel and Building Material
- Carbohydrates: include both sugars and polymers of sugars
- The simplest carbohydrates are monosaccharides (simple sugars) -- Disaccharides are double sugars -- two monosaccharides joined by condensation reaction
Sugars
- Monosaccharides have some multiple of unit CH2O
- Glucose is the most common monosaccharide -- central importance to the chemistry of life (know other examples such as fructose and galactose - not structure but names)
- Molecule has carbonyl group and multiple hydroxyl groups
- Glucose has ring formed - Know this
(from Figure 5.4 on Online Website)
Figure 5.4
Figure 5.4

- Monosaccharides are a major nutrient for cells
- Cellular respiration is when cells extract energy from glucose molecules
- Disaccharide is two monosaccharides joined by a glycosidic linkage - a covalent bond formed between two monosaccharides by dehydration reaction (sugar is a disaccharide-sucrose-with two monomers of glucose and fructose)
- Plants transport carbohydrates from leaves to roots
- Lactose is the sugar present in milk and is a disaccharide
- Polysaccharide are macromolecules with hundreds of monosaccharides jointed with glycosidic linkages.
- They serve as storage materials and building materials for structures that protect the cell and organisms
- Starch is a storage polysaccharide of plants- it is a polymer consisitng of entirely glucose monomers.
- Plants store starch within their chloroplast - it serves as cellular fuel and represents stored energy
- Animals store polysaccharides called glycogen- it is a polymer of glucose - stored mainly in the liver and muscle cells - hydrolysis of glycogen in these cells releases glucose when there is a demand for sugar
- Organisms build strong materials from structural polysaccharides - like cellulose - a major component of plant cell walls
- Cellulose is a polymer of glucose but has different glycosidic linkages
- Cellulose has a three dimensional shape but starh has a helical shape - cellulose is straight and never branches
- Many organisms do not have the enzyme needed to digest cellulose - humans do not - the cellulose passes through the digestive tract and is eliminated - the cellulose abrades the wall of the digestive tract and helps food pass through smoothly
- Chitin the carbohydrate used by arthropods to build their exoskeletons - hard case that surrounds the softer parts of an animal
- Chitin is similar to cellulose - the glucose monomer of chitin has a nitrogen-containing appendage.

5.3: Lipids are a Diverse Group of Hydrophobic Molecules
- Lipids are the molecules that do not consist of polymers
- Lipids are grouped together because they share one important shape: they have little to no affinity to water - hydrophobic - may have some polar bonds but most of lipids consist of hydrocarbons
- Fats are large molecules assembled from smaller molecules by dehydration reaction - constructed of glycerol and fatty acids
- A fatty acid has a long carbon skeleton (16-18 carbon atoms) - one end of fatty acid is carboxyl group (funtional group) - hydrocarbon chain is attached to carboxyl group ( reason it is hydrophobic)
Figure 5.11
Figure 5.11
(From Online Textbook-Figure 5.11)
- To make a fat three fatty acid molecules bind to glycerol by ester linakge (bond between a hydroxyl group and a carboxyl group) resulting fat is a triacylglycerol
- Fatty acids vary in length and location of the double bonds
- There are saturated and unsaturated fats - refers to the structure of the hydrocarbon chains of the fatty acids
- Saturated Fatty Acid - no double bonds between carbon atoms composing the chain - as many hydrogen atoms as possible bind to skeleton
- Unsaturated Fatty Acid - one or more double bond - formed by the removal of hydrogen atoms from teh carbon skeleton

Figure 5.12
Figure 5.12
(From Online Book - Figure 5.12)
- Most animal fats are saturated - lard and butter - solid at room temperature
- Plants and fish fats are unsaturated - liquid at room temperature - oils
- Saturated fats in excess in diet leads to cardiovascular diseases - atherosclerosis - build up impedes blood flow in blood vessels
- Major function of fats is energy storage - stores more than polysaccharides (starch) - useful for animals since they must carry their stored energy
- Phospolipid - similar to a fat - has only two fatty acids attached to a glycerol (instead of three)
- Hydrocarbon tails are hydrophobic and heads are hydrophilic - bilayer as boundry between cell and the external enviroment
- Steroids are lipids characterized by a carbon skeleton with four fused rings
- Cholesterol is a type of steroid that is common in animal cell membranes - crucial molecule in animals - synthesizes sex hormones
Figure 5.15
Figure 5.15
(Figure 5.15 from Online Textbook)
Chapter 5
organization is the key to life
protein- consists of one or more polypeptides folded and coiled into a specific conformation (end in –ase)

Protein Structure
- all proteins are constructed from the same set of 20 amino acid monomers, but The shape determines the function
- Amino Acids- organic molecules with both carboxyl and amino groups
· at the center is the alpha carbon with 4 components attached
1.
See full size image
See full size image
hydrogen adam

2. carboxyl group
3. amino group
4. variable Rà 20-can be as simple as hydrogen atom or a carbon skeleton with functional groups attached
Non-polar- hydrophobic
Polar- hydrophillic
Acidic- carboxyl group
Base- amine side group
· amino acids are joined together when a dehydration reactions removed a hydroxyl group from the carboxyl end of one amino acid and a hydrogen from the amino group of another à resulting covalent bond forms a peptide bond (*Note: repeating this process froms a polypeptide chain)

- polypeptide- polymers of proteins
- levels of stucture
1. primary- is the unique sequence of amino acids
2. secondary- coils and folds that result from the hydrogen bonds between the constituennts of the polypeptide backbone
3. tertiary- determined by interactions among various R groups
4. quarternary- results from the aggregation of two or more polypeptides
Protein Shape determines function
- proteins can be globular or fibrous
- pH, salt concentration, temperature, other factors can unravel/ dentature a protein
- the folding of proteins is assisted by chaperonins
Protein Functions
- structural support
- storage
- transport
- cellular signaling
- movement
- defense against foreign substances
- catalysts
protein enzymes function as catalysts- regulating metabolism by selectively accelerating chemical reactions without being consumed

Nucleic Acids Store and Transmit Hereditary Information
RNA- ribonucleic acid DNA- deoxyribonucleic

Nucleic Acids- polymers made of nucleotide monomers (3 parts: nitrogenous base, pentose sugar, phosphate group)
Nitogenous Bases:
Pyrimidines- CUT- Cytosine, tymine, uracel
Purine- Pure as Gold- Adenine, Guanine